Update on "[build] Add editable mode unittest"

As titled. To do this we need to refactor the arguments being passed
into `setup-linux.sh` `setup-macos.sh` and `unittest-linux.sh`
`unittest-macos.sh`.

[ghstack-poisoned]

Author: larryliu0820

setup.py

@@ -360,7 +360,7 @@ def __init__(self, src: str, modpath: str):
             "/" not in modpath
         ), f"modpath must be a dotted python module path: saw '{modpath}'"
         # This is a real extension, so use the modpath as the name.
-        super().__init__(src=src, dst=modpath, name=modpath)
+        super().__init__(src=f"%CMAKE_CACHE_DIR%/{src}", dst=modpath, name=modpath)
 
     def src_path(self, installer: "InstallerBuildExt") -> Path:
         """Returns the path to the source file, resolving globs.